Hickey made international headlines in February 1939, when, as Lord Mayor of Cork, he refused to give a civic reception to the captain and crew of the German warship SMS Schlesien which was on a 'courtesy visit' to Cork Harbour flying the Nazi flag (in spite of Irish neutrality). The Schlesien was a 13,000 tonne World War I battleship. Hickey's reasoning for the refusal to entertain the German crew was stated to be a slight by the German media on the occasion of the death of Pope Pius XI some time earlier. Hickey said, "the insult given to the Catholic world on the death of the Pope, when the responsible German Press termed our Holy Father a political adventurer”.[2][3]

Hickey was one of the six TDs who left Labour in 1944 to form the National Labour Party, and it was as a National Labour Party candidate that he was defeated at the 1943 and 1944 general elections. He was re-elected at the 1948 election as a National Labour candidate, and after the split in Labour was healed, he was returned to the Dáil for a final time at the 1951 general election.[4]